Pirolidinski derivati u organokatalitičkim transformacijama
Pyrrolidine derivatives in organocatalytic transformations
Doktorand
Jovanović, Predrag M.Mentor
Savić, VladimirČlanovi komisije
Tešević, VeleFerjančić, Zorana
Maslak, Veselin
Nikodinović-Runić, Jasmina
Metapodaci
Prikaz svih podataka o disertacijiSažetak
Hiralni, polisupstituisani derivati pirolidina, dobijeni cikloadicionim reakcijama
azometinskih ilida, proučavani su kao organokatalizatori u Michael-ovoj reakciji aldehida/ketona
i vinil-sulfona. Pod optimalnim reakcionim uslovima, u kojima se koristilo 10 mol % katalizatora
u vlažnom metilen-hloridu prinosi reakcija su generalno bili dobri dok je enantioselektivnost
varirala dostižući 52 %.
Razvijen je efikasan biokatalizator za asimetričnu Michael-ovu adiciju acetaldehida na β-
nitrostiren na bazi celih ćelija koja eksprimira 4-oksalokrotonat tautomerazu (4-OT). Utvrđen je
optimalan odnos supstrata i biokatalizatora. Kada je kao supstrat korišćen β-nitrostiren dobijena
je odlična enantioselektivnost (e.e. >99%) uz prinos reakcije do 60%. Biokatalizator je manje
efikasan sa p-hlor-, o-hlor- i p-fluor-β-nitrostirenom gde su dobijeni prinosi od 38%, 51%, 31% i
e.e. 84%, 88%, 94%...
Chiral, polysubstituted pirrolydines derivatives, obtained via cycloaddition reactions of
azomethine ylides, were studied as organocatalysts in the Michael reaction of aldehydes/ketones
and vinylsulphones. Under optimised reaction conditions employing 10 mol % of the catalyst in
wet CH2Cl2, the yields of the products were generally good while the enantioselectivity varied,
reaching up to 52 %.
A novel whole cell system based on recombinantly expressed 4-oxalocrotonate
tautomerase (4-OT) was developed and shown to be an effective biocatalyst for the asymmetric
Michael addition of acetaldehyde to β-nitrostyrenes. Optimal ratio of substrates and biocatalyst
was determined. Excellent enantioselectivity (>99% ee) and product yields of up to 60% were
obtained with β-nitrostyrene substrate. The biocatalyst exhibited lower reaction rates with pchloro-,
o-chloro- and p-fluoro-β-nitrostyrenes with product yields of 38%, 51%, 31% and ee
values of 84%, 88% and 94% respectively...